Anne de l'Hospital, lieutenant general of the armies of the king and squire of Gaston, Duke of Orléans. Guillaume's mother, Elisabeth, was the daughter of Claude Gobelin, administrator (intendant) of the armies of the king and a counsellor of state. The l'Hospitals were an old aristocratic family with distinguished service to the king since 1488.

Although I do not have a definite statement, I do not see how one can avoid the conclusion the l'Hospital grew up in wealthy circumstances.

3. Nationality

Birth: French

Career: French

Death: French

4. Education

Schooling: No University

As soon as he was old enough to bear arms, he obtained a commission of captain in the cavalry, but he had already, by that time, acquired a passion for mathematics from his tutor.

In 1692, Jean Bernoulli visited Paris. It is not clear that he taught l'Hospital, but after Bernoulli had been there a few months, l'Hospital returned to Ourques, Touraine, embued with the new mathematics.

5. Religion

Affiliation: Catholic (assumed)

6. Scientific Disciplines

Primary: Mathematics

His fame was based on his book Analyse des infiniment petits pour l'intelligence des lignes courbes (1696), the first textbook of the differential calculus. At his death he left the completed manuscript of a second book, Traité analytique, which was published in 1720.

7. Means of Support

Primary: Personal Means

He served for a time as a cavalry officer but resigned from the army. From that time onwards he devoted himself entirely to mathematics. He had an estate that must have supported him. He had the titles of Marquis de Sainte-Mesme and Comte d'Entremont. Fontenelle also calls him Seigneur d'Ourques, la Chaise, le Bréau, et autres lieux.

8. Patronage

Type: Court Official

L'Hospital was named premier titulaire honorary member of the Académie by Louis XIV.

9. Technological Involvement

Type: None

10. Scientific Societies

Membership: Académie Royal des Sciences

1693, académicien géomètre.

1699, honorary member of the Académie.

1702 & 04, vice president of the Académie.

Correspondence with Leibniz, with Jean Bernoulli, and with Huygens. According to Fontenelle it was he who introduced Huygens to the new calculus.

Sources

Fontenelle, Eloge, in the Histoire de l'Académie des Sciences for 1704, p. 154-68.